Identifying candidate genes for sugar accumulation in sugarcane: an integrative approach

Area of Science:

• Plant genomics
• Crop science
• Molecular breeding

Background:

• Sugarcane genome sequencing is challenging due to its large size, polyploidy, and aneuploidy.
• Understanding sugarcane genetics is crucial for developing improved cultivars.
• Synteny analysis with related species aids in identifying genes for agronomic traits.

Purpose of the Study:

• To identify candidate genes associated with sugar accumulation in sugarcane.
• To leverage synteny between sorghum and sugarcane for gene discovery.
• To explore gene expression patterns related to sugar content.

Main Methods:

• Utilized sorghum Brix quantitative trait loci (QTL) to screen sugarcane bacterial artificial chromosome (BAC) libraries.
• Confirmed synteny and collinearity between sorghum and sugarcane genomes.
• Performed manual annotation, RNA-sequencing, coexpression network analysis, and identified differentially expressed genes (DEGs).

Main Results:

• Successfully recovered and confirmed the syntenic genomic region between sorghum and sugarcane.
• Identified 51 genes in sugarcane varieties, also present in Saccharum spontaneum.
• Discovered three candidate genes potentially involved in sugar accumulation: an ethylene-responsive transcription factor (ERF), an ABA 8'-hydroxylase, and a prolyl oligopeptidase (POP).

Conclusions:

• The identified candidate genes offer targets for molecular breeding to enhance sugar accumulation in sugarcane.
• This approach can be applied to discover genes for other important agricultural traits.
• Findings contribute to a deeper understanding of sugarcane genetics and breeding strategies.